The speech we hear is an indication of that which we don't hear. It is a necessary avoidance, a violent, sly, anguished or mocking smokescreen which keeps the other in its place.
"The great advantage of being a writer is that you can spy on people. You're there, listening to every word, but part of you is observing. Everything is useful to a writer, every scrap, even the longest and most boring of luncheon parties."